As a Potentially Historic El Niño Forms, Scientists Debate Climate Change's Role

The tropical Pacific Ocean is heating up, signaling the arrival of a climate phenomenon that routinely reshapes global weather. In June 2026, both the National Oceanic and Atmospheric Administration (NOAA) and the World Meteorological Organization (WMO) officially declared the onset of El Niño conditions.[2][3]

This naturally occurring climate pattern, characterized by unusually warm sea-surface temperatures in the central and eastern equatorial Pacific, occurs every few years when trade winds weaken. The shift in ocean heat triggers a cascade of atmospheric changes, altering jet streams and precipitation patterns worldwide.[3][5]

But as this new El Niño develops, a vigorous debate is unfolding within the scientific community: Is human-caused climate change fundamentally altering the mechanics of El Niño, making the phenomenon itself more intense?[1][6]

The stakes of this question are immense. NOAA currently forecasts a 63 percent chance that the 2026 event will become a "very strong" El Niño by the Northern Hemisphere winter, meaning sea-surface temperatures could rise more than 2.0 degrees Celsius above average.[3]

If those forecasts hold, the world could be facing an ocean heat engine rivaling the historic, highly destructive El Niño events of 1997-1998 and 2015-2016.[3]

To understand the debate over climate change's role, researchers divide the issue into two distinct questions: the "baseline effect" and the "mechanistic effect." The evidence for the former is absolute; the evidence for the latter remains highly contested.[6]

On the baseline effect, the scientific consensus is unified. Because the planet's average temperature is already significantly higher due to greenhouse gas emissions, any natural El Niño event is now occurring on top of a hotter foundation.[2][4]

The WMO warns that this combination will "pour fuel on the fire of a warming world." A previous El Niño helped drive global average temperatures to a record 1.55 degrees Celsius above preindustrial levels, and the 2026 event threatens to push the mercury even higher.[2]

Because the atmosphere is warmer, it holds more moisture. The Intergovernmental Panel on Climate Change (IPCC) concluded in its Sixth Assessment Report that it is "very likely" that the precipitation variance related to El Niño will increase in the long term.[4]

In practical terms, this means the extremes are amplified. When El Niño brings rain to the southern United States or parts of South America, the downpours are heavier and more prone to causing catastrophic flooding.[4][6]

Conversely, when it brings dry conditions to Australia or Southeast Asia, the droughts are more severe, supercharging the risk of wildfires across millions of acres of vulnerable terrain and threatening global crop yields.[2]

However, the mechanistic effect—whether climate change is actually causing the ocean-atmosphere cycle of El Niño to swing more violently—remains the subject of intense academic dispute.[1]

Some attribution researchers point to the fact that the most intense El Niño events on record have all occurred in recent decades. They argue that the immense accumulation of upper-ocean heat is altering the frequency and amplitude of the El Niño-Southern Oscillation (ENSO) cycle.[1][6]

Yet, the IPCC's official stance urges caution. The AR6 report states there is currently "no clear evidence" of long-term trends in ENSO behavior that can be definitively distinguished from natural, internal climate variability.[4]

The climate system is inherently chaotic. Climate models run over thousands of simulated years without human greenhouse gas emissions still produce periods where El Niño events cluster together or become unusually strong, purely by chance.[4][6]

Regardless of whether the engine itself is changing, the immediate impacts of the 2026 El Niño are already materializing. Coastal communities face a "double whammy" of decades of sea-level rise combined with El Niño-driven storm surges, proving that while the mechanics of El Niño may be natural, the damages it inflicts are increasingly man-made.[3][6]